JP2003005358A - Image forming material and original plate for planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming material suitable for use in an original plate for a planographic printing plate for scanning exposure adapted to a heat mode recording system, that is, an image forming material having high sensitivity to semiconductor laser light, excellent in storage stability, developable with water or an aqueous alkali solution or exhibiting such good on-machine developability that the material is attached to a printing machine as it is without developing to enable printing and ensuring further improved printing resistance of a printing surface. SOLUTION: The image forming material contains at least one of compounds represented by formulae (I)-(III) (where R1 is a n-valent organic residue ((n) is an integer of 2-8); R2 -R4 are each alkyl; X is a releasable group bonding to N through O; Y is H, a metal atom or trialkylsilyl; and Ar is an aromatic group).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel image forming material and a lithographic printing plate precursor. The present invention also relates to an image forming material which can be suitably used as a lithographic printing plate precursor for scanning exposure, which is suitable for a CTP system which is particularly excellent in workability and economy.

[0002]

2. Description of the Related Art Generally, a lithographic printing plate comprises an oleophilic image area which receives ink during a printing process and a hydrophilic non-image area which receives fountain solution. As such a lithographic printing plate precursor, conventionally, a PS plate provided with a lipophilic photosensitive resin layer (ink receiving layer) on a hydrophilic support has been widely used. After the mask exposure through the lith film, the non-image area was dissolved and removed by a developing solution to obtain a desired printing plate.

In recent years, various new image output systems have come into practical use, which correspond to the digitization technique of electronically processing image information using a computer. Along with this, computer-to-plate (CTP) technology, which scans active radiation with high directivity such as laser light according to digitized image information and directly produces a printing plate without passing through a lith film, has long been desired. However, it has become an important technical subject to obtain a printing plate precursor suitable for this.

On the other hand, the plate making process in the conventional PS plate is as follows.
After the exposure, a step of dissolving and removing the non-image area by a wet process is indispensable, which is another problem to be improved. Particularly in recent years, consideration of the global environment has become a major concern of the entire industry. From the viewpoints of both such environmental aspects and the rationalization of the process that accompanies the aforementioned digitalization, simplification of processing, dry processing, and non-processing are more than ever possible.
It is strongly desired.

From this point of view, the following method has been proposed as one of the methods for eliminating the conventional processing steps. That is, the photosensitive layer (image forming layer) is used so that the non-image part of the printing plate precursor can be removed during the normal printing process. There is an on-press development method for obtaining a specific printing plate. However, the major problem with the on-press development method is that the original plate remains
Since the photosensitive layer is not fixed, there has been a big problem that the plate must be completely protected from light and / or kept at a constant temperature until it is mounted on a printing machine.

In response to the above technical problems, recently, as a method of manufacturing a printing plate by scanning exposure, a semiconductor laser, YA
Since high-power solid-state lasers such as G lasers have become available at low cost, methods using these lasers have been particularly promising. In the high power density exposure system using these high power lasers, various phenomena different from the conventional photoreaction used in the photosensitive material system for low to medium power density exposure can be utilized. Specifically, in addition to chemical changes, structural changes such as phase changes and morphological changes can be used. Usually, such a recording method using high power density exposure is called heat mode recording, and the light energy absorbed in the photosensitive material is converted into heat, and the generated heat causes
This is because it is believed that the desired phenomenon is triggered.

A major advantage of such a heat mode recording system is that fixing of an image after exposure is not essential. That is, the phenomenon used for image recording of the heat mode sensitive material is
The fixing of the image after exposure is not essential as it does not substantially occur under normal intensity light exposure or normal ambient temperature. Therefore, for example, even if a photosensitive layer that is insolubilized or solubilized by heat mode exposure is used, and the image is obtained by performing development (removing the non-image area) after exposure to ambient light for an arbitrary time after image exposure. A system that does not change is possible. Therefore, according to the heat mode recording,
It is also possible to obtain a lithographic printing plate precursor which is desirable for the on-press development method described above.

As one of the preferred methods for producing a lithographic printing plate based on heat mode recording, a hydrophilic image forming layer is provided on a hydrophilic support, and the image is exposed to the heat mode imagewise to dissolve the hydrophilic layer. A method has been proposed in which dispersibility is changed and, if necessary, the unexposed portion is removed by wet development.
Further, the conventional heat mode system original plate has another big problem that the stain resistance of the non-image portion is poor or the strength of the image portion is weak. That is, there was a need for improvement in that the change in solubility due to exposure in the vicinity of the support in the image forming layer was smaller than that in the vicinity of the surface of the image forming layer. In the heat mode system original plate, since the heat generation during the heat mode exposure is based on the light absorption of the light absorber in the recording layer, the heat generation amount is large on the recording layer surface and small in the vicinity of the support. Therefore, the degree of change in solubility of the recording layer in the vicinity of the support becomes relatively small. As a result, in the heat mode negative-type original plate, the ink-receptive layer was often removed during the development and / or printing process in the exposed area where the originally hydrophobic ink-receptive layer should be provided. Such removal of the image area ink-receptive layer in the negative master causes a problem of poor printing durability in terms of printing performance. In particular, when a metal support having a high thermal conductivity such as aluminum, which is preferable in terms of printability, is used, thermal diffusion further hinders the temperature rise in the vicinity of the support, so that the above-mentioned problems are notable. is there. In order to obtain a sufficient change in the solubility in the vicinity of the substrate, extremely large exposure energy was required, or post-treatment such as heating after exposure had to be performed.

For example, as described in Japanese Patent No. 2938397, thermoplastic hydrophobic polymer fine particles are thermally fused by infrared laser exposure to form an image,
There is a method of mounting the plate on a cylinder of a printing machine and performing on-press development with dampening water and / or ink. However, in such a method of forming an image simply by heat fusion, although good on-press developability is exhibited, when a heat-sensitive layer (image forming layer) is directly provided on an aluminum substrate, generated heat is absorbed by the aluminum substrate. Therefore, the reaction does not occur on the interface between the substrate and the heat-sensitive layer, and the printing durability becomes insufficient.

In addition, JP-A-52-121319 discloses a positive type composed of a compound (for example, a diazonium compound) which decomposes with light and heat, substance particles capable of absorbing light and converted into heat, and a binder. An image recording material is disclosed which decomposes a diazonium compound by heat to record an image.

Further, Japanese Patent Laid-Open No. 164049/1987,
Japanese Unexamined Patent Publication (Kokai) No. 6-1088 discloses a light-sensitive material in which a blocked isocyanate is combined with a photothermal conversion substance. However, these use a low-molecular type blocked isocyanate, so that the sensitivity and printing durability are insufficient. there were. Also,
U.S. Pat. No. 5,360,836 describes monomer compounds having a blocked isocyanate structure and a polymerizable double bond. However, with a negative-type recording material using a blocked isocyanate compound, it is possible to perform heat recording using a solid-state laser / semiconductor laser (heat mode) having an emission region from infrared to near infrared, and such recording None of them had good sensitivity and storage stability.

[0012]

As described above, after image recording, development is possible without post-heating, or on-press developability is good, sensitivity is high, and heat sensitivity showing high printing durability. The present situation is that the photosensitive material of No. 1 has not been obtained yet. Therefore, an object of the present invention is to provide an image forming material suitable for a lithographic printing plate precursor for scanning exposure which is suitable for a heat mode recording method, that is, a high sensitivity to a semiconductor laser and an excellent storage stability. It shows good on-press developability that can be developed with water, an aqueous alkaline solution, or can be mounted on a printing machine as it is without being developed and printed, and further improved in printing durability on the printing surface. An object is to provide the image forming material.

[0013]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies in order to achieve the above object, and as a result, have found that the drawbacks of the prior art can be overcome by adopting the following configuration. That is, the present invention is as follows. (1) An image-forming material containing at least one compound selected from the compounds represented by the following general formulas (I) to (III).

[0014]

[Chemical 2]

(In the formulas (I) to (III), R ₁ represents an n-valent organic residue (n is an integer of 2 to 8), R _{2 to} R ₄ represent an alkyl group, and X represents oxygen. A leaving group bonded to N by an atom, Y represents a hydrogen atom, a metal atom, a trialkylsilyl group, and Ar represents an aromatic group.) (2) On the hydrophilic support, the above general formula ( A lithographic printing plate precursor having an image forming layer comprising fine particles containing at least one compound represented by I) to (III).

With the lithographic printing plate precursor using the image forming material of the present invention, a lithographic printing plate having high printing durability can be prepared without post-heating. Further, in a mere heat-fusion-free printing plate of thermoplastic fine particles, the film strength was insufficient and the printing durability was insufficient, but by using the lithographic printing plate precursor of the present invention, high printing durability was obtained. It is possible to create a printing plate of. As explained above,
The image-forming material of the present invention contains at least one compound having a structure represented by any one of the above general formulas (I) to (III), and causes a chemical reaction by heating to easily give an isocyanate having a high reaction activity. Containing a structure that produces
The lithographic printing plate precursor using this image-forming material is heated by irradiation with laser exposure to generate an isocyanate, which is a compound having a nucleophilic group in the image-forming layer or self-hydrolyzed by water. Printing durability can be improved because it reacts with the generated amine to form a strong film. Therefore, as described below, by applying the compound of the present invention to a lithographic printing plate precursor comprising an image forming layer containing thermoplastic fine particles, a development treatment such as water development or an alkali development method, or a development treatment is required. It can be mounted directly on the printing machine for plate making and printing, and has high hydrophobic / hydrophilic discrimination (identification),
It is possible to provide a lithographic printing plate precursor that has good ink receptivity and printing durability and can obtain clear printed matter. Further, the image forming material of the present invention has a structure in which the reactive isocyanate group is made into a precursor, whereby a lithographic printing plate precursor having improved storage stability can be provided.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The image forming material and the lithographic printing plate precursor of the invention are described in detail below. The image forming material of the present invention contains at least one compound represented by the following general formulas (I) to (III). The compounds represented by formulas (I) to (III), which are characteristic constituent elements of the image-forming material of the present invention, will be specifically described below.

[0018]

[Chemical 3]

In the formulas (I) to (III), R ₁ represents an n-valent organic residue, and n represents an integer of 2 to 8. R ₁ is an n-valent organic residue selected from an n-valent aliphatic group, an n-valent aromatic group, an n-valent heterocyclic group and a combination thereof, wherein an aliphatic group, an aromatic group and a heterocyclic group are used. The group may have a substituent. In addition, -O-, -S-, -CO-, -NH
A divalent linking group may be formed by a combination with a linking group selected from —, —SO ₂ — and —SO—. The aliphatic group preferably has 1 to 60 carbon atoms, and 1
It is more preferably from 30 to 30, more preferably from 1 to 20, and most preferably from 1 to 10. The aliphatic group may be unsaturated (having a double bond or a triple bond). The aliphatic group may have a cyclic structure or a branch. The aromatic group preferably comprises a benzene ring or a naphthalene ring, more preferably a benzene ring. Heterocyclic group is 3
It preferably has a member to 10-membered heterocycle, more preferably a 4- to 8-membered heterocycle, and most preferably a 5- or 6-membered heterocycle. The hetero atom of the hetero ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. The heterocycle may be condensed or spiro-bonded with an aliphatic ring, an aromatic ring or another heterocycle. Examples of the heterocycle include pyrrolidine ring, piperidine ring, piperazine ring, morpholine ring, tetrahydrofuran ring, tetrahydropyran ring, tetrahydrothiophene ring, dioxane ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, triazine ring, furan ring. , Thiophene ring and isocyanuric ring. Examples of the substituent of the aliphatic group, aromatic group and heterocyclic group include hydroxyl, halogen atom (eg, chlorine atom), cyano, amino, substituted amino group, heterocyclic group, acyl group and acyloxy group. . The substituent of the substituted amino group is preferably an alkyl group or an aryl group. The aromatic group and the heterocyclic group may have an alkyl group as a substituent. Specific preferred examples of R ₁ are shown below, but the invention is not limited thereto.

[0020]

[Chemical 4]

[0021]

[Chemical 5]

[0022]

[Chemical 6]

R _{2 to} R ₄ represent an alkyl group having 1 to 12 carbon atoms and may be the same or different. The alkyl group may have a cyclic structure or a branch. X represents a leaving group bonded to the nitrogen atom with an oxygen atom. For example, -OR
(R: alkyl group having 1 to 12 carbon atoms, aryl group),-
_{O-CO-R 5 (R} 5: an alkyl group, an aryl group having 1 to 12 carbon _{atoms), - O-SO 2 -R} 5 (R: alkyl group having 1 to 12 carbon atoms, an aryl group). Y represents a hydrogen atom, a monovalent or divalent metal atom (for example, a sodium atom, a potassium atom, a silver atom) or a trialkylsilyl group of an alkyl group having 1 to 12 carbon atoms, and Ar represents an aromatic group. It is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.
The heterocyclic group preferably has a 3- to 10-membered heterocycle, more preferably a 4- to 8-membered heterocycle, and most preferably a 5- or 6-membered heterocycle. The hetero atom of the hetero ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. Ar may have a substituent.

A single compound represented by the formulas (I) to (III) can be used in the image forming layer of the present invention.
More than one compound can be used. The compounds having the structures represented by the general formulas (I) to (III) of the present invention can be synthesized with reference to the following documents. References for compounds of general formula (I): 1) Guerrke, Justu
s Liebigs Ann. Chem., 205 , 291,1880; 2) Jones, JA
mer.Chem.Soc., 44 , 417, 1922; 3) Jones, J. Amer. Chem.
Soc., 46 , 2526, 1922; 4) Stafford, J. Org. Chem., 63 , 10
040, 1998. References for compounds of general formula (II): Furukawa, Bull.Che
m.Soc.Jpn., 51 , 3599, 1978. References for compounds of general formula (III): Rigaudy, Tetrahed
ron Lett, 21 , 3367, 1980. Hereinafter, in the general formulas (I) to (III), preferable specific examples of the structure of the organic residue are shown, except for the n-valent organic residue.
The present invention is not limited to these.

[0025]

[Chemical 7]

[0026]

[Chemical 8]

[0027]

[Chemical 9]

[0028]

[Chemical 10]

(Image Forming Layer) The image forming layer (heat sensitive layer) which is a characteristic part of the lithographic printing plate precursor according to the invention will be described. The lithographic printing plate precursor using the image-forming material of the present invention comprises, as described above, at least one compound having a structure represented by the general formulas (I) to (III) on a hydrophilic support. It has an image-forming layer formed by applying a coating liquid containing a composition containing a fine-particle or solid dispersion containing a certain compound and a photothermal conversion substance. Further, by adding a compound having a nucleophilic group to the image forming layer, a stronger crosslinked film can be formed. . Examples of the nucleophilic group include a hydroxyl group, amino group, mercapto group, carboxyl group, active methylene group, heterocyclic group and active methylene group. The compound may be either a monomer or a polymer, but is preferably a polymer. The image forming layer may be formed in such a state that these compounds are dissolved in the compound of the present invention, in the form of fine particles containing either one, or in the form of fine particles containing both of them. Specific examples of preferable repeating units in the case of a polymer having a nucleophilic group are shown below, but the present invention is not limited thereto.

[0030]

[Chemical 11]

[0031]

[Chemical 12]

When a compound having a nucleophilic group is added to the image forming layer, the following method can be exemplified. An image-forming layer containing at least one of the compounds represented by the general formulas (I) to (III) and a polymer containing the nucleophilic group as a polymer film, an image containing fine particles or a solid dispersion state. It is arranged as a forming layer. At least one of the compounds represented by the general formulas (I) to (III), or the polymer film containing the nucleophilic group, is arranged in the form of fine particles or a solid dispersion.
At least one of the compounds represented by the general formulas (I) to (III) and the polymer having the nucleophilic group are both arranged in the form of fine particles or solid dispersion.

When the above-mentioned image forming material has an image forming layer of a polymer film, the film thickness thereof is from 0.2 μm to 5 μm.
μm is preferable, and more preferably 0.5 μm to 2 μm. When the above-mentioned image-forming material is in the form of fine particles or / and solid dispersion state, the particle size is 0.01.
μm to 50 μm is preferable, and more preferably 0.05 μm
10 μm range, and most preferably 0.05 μm
It is in the range of 2 μm. The larger the polymer particles, the smaller the resolving power of the image-forming material. On the contrary, when the polymer particles are too small, the discrimination of hydrophilicity and hydrophobicity tends to decrease and the image-forming property tends to deteriorate. Regardless of the constitution described above, the general formulas (I) to (III) of the present invention can be used.
The content of the compound represented by
The range of 9 wt% is preferable, and the range of 25-90 wt% is more preferable.

The particles or solids may be dispersed by a solid dispersion method in which the image-forming material of the present invention is added to a non-solvent and pulverized, or by dissolving it in a solvent in which the image-forming material of the present invention is soluble. Emulsion dispersion or emulsion dispersion solvent that does not dissolve in a solvent and emulsifies and disperses it in another non-solvent that does not dissolve these compounds by using a homomixer, etc., and volatilizes and removes solvent components as necessary to form solid particles. Evaporation method can be used. When using these methods, a surfactant or a polymer component capable of stabilizing dispersion may be added to stabilize the particle state. When the emulsification dispersion method is used, the particles may be prepared by mixing with the image-forming material of the present invention and another organic polymer component as a particle constituent component. Further, these particles may have a core-shell structure covered with another polymer as a core component, further,
The shell component may be three-dimensionally crosslinked. When the polymer of the image forming material is a high molecular weight substance, it may be made into particles by using a known method for producing fine polymer particles such as a dispersion polymerization method or an emulsion polymerization method.

In the image forming layer, in addition to the compounds represented by the general formulas (I) to (III) of the present invention and the compound containing a nucleophilic group, a thermoplastic polymer, a hydrophilic polymer and A photothermal conversion substance can be included. Also,
The image forming layer of the lithographic printing plate precursor using the light-sensitive material of the present invention may further contain a thermoplastic polymer. The addition of this thermoplastic polymer causes melting and fusion of the polymer due to heat, and is expected to improve the hydrophobic effect.
It is preferable that the thermoplastic polymer is in the form of fine particles because the melting and fusing effects are easily exhibited. In order to easily exhibit this melting and fusing effect, the glass transition temperature of the polymer is 150 ° C. or lower, more preferably 120.
It is preferable to use a material having a temperature of ℃ or less. Glass transition temperature is 1
When the temperature is 50 ° C. or higher, heat fusion of the polymer hardly occurs,
It is difficult to form a strong image with a laser having a relatively small output. Although the lower limit of the glass transition temperature is not particularly limited, it is preferably about 10 ° C or higher. If the glass transition temperature is too low, when the coating liquid containing fine particles of this polymer is applied to the substrate and dried to form the recording layer, the separation of the fine particles by the binder resin is incomplete. May occur, and an image forming layer in which particles are dispersed may not be formed well.

Specific examples of thermoplastic polymers suitable for use in the present invention include polyethylene, polyvinyl chloride, methyl poly (meth) acrylate, ethyl poly (meth) acrylate, polybutylmethacrylate, and the like. Polyhydroxyethyl methacrylate, polyglycidyl methacrylate, polystyrene, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, poly-p
-Hydroxystyrene, poly-m-hydroxystyrene, phenol resin, cresol resin, epoxy resin,
Examples thereof include polyurethane, polyester, polycarbonate, polyvinylidene chloride, polyacrylonitrile, polyvinylcarbazole, and the like, or copolymers thereof. The molecular weight of the thermoplastic polymer is 5,000 to 100
It can be selected from the range of 000. When the thermoplastic polymer is in the form of fine particles, the particle size thereof is preferably 0.01 μm to 50 μm, more preferably 0.0
5 μm to 10 μm range, and most preferably 0.05
It is in the range of μm to 2 μm. The larger the polymer particles, the smaller the resolving power of the thermal recording material. On the other hand, when the polymer particles are too small, the hydrophilic and hydrophobic discrimination is deteriorated and the image forming property tends to be deteriorated. Such polymer particles are preferably present as a dispersion in an aqueous coating liquid from the viewpoint of stability, and an aqueous dispersion of such polymer particles is described in US Pat. No. 3,47,47.
It can be produced by the method disclosed in 6,937.

Another method which is particularly suitable for producing an aqueous dispersion of a thermoplastic polymer is (1) dissolving the hydrophobic thermoplastic polymer in a water immiscible organic solvent,
There may be mentioned a method comprising the steps of (2) dispersing the solution thus obtained in water or an aqueous medium, and (3) removing the organic solvent by evaporation. The blending amount of the hydrophobic thermoplastic polymer fine particles contained in the image forming layer is
It is preferably in the range of 1 to 90% by weight, more preferably 10 to 8%.
It is in the range of 0% by weight. If the amount is too small,
From the viewpoint of improving the hydrophobicity in the exposed area, the effect of adding this polymer is insufficient. On the other hand, if the blending amount of the hydrophobic thermoplastic polymer fine particles is too large, the hydrophilic layer in the non-exposed area becomes This may affect the ink receptivity in the non-image area and stain the non-image area.

According to the image forming layer containing such thermoplastic polymer fine particles, the pattern region where an image is to be formed is directly heated, or the pattern region which can convert light into heat is included. In the imagewise heating or exposure area in the image forming layer, the hydrophobic thermoplastic polymer fine particles are softened or melted by exposure while being brought into contact with the original. The hydrophobicity in the region of is improved.

(Hydrophilic Polymer) A hydrophilic resin may be added to the image forming layer of the lithographic printing plate precursor using the image forming material of the present invention. The addition of the hydrophilic resin not only improves the on-press developability, but also improves the film strength of the image forming layer itself. Further, the resin can be crosslinked and cured to give a lithographic printing plate precursor that does not require development. Further, by using a polymer having active hydrogen for these hydrophilic resins, it is possible to react with an isocyanate group released from the image-forming material of the present invention and to form a stronger film. Furthermore, by disposing an acidic group capable of acid-base interaction with the polyfunctional base released from the base generator in the hydrophilic resin, crosslink formation occurs due to the acid-base interaction, and a stronger film can be formed. As the hydrophilic resin, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl, and carboxymethyl, and hydrophilic sol-gel conversion binder resins are preferable.

Specific examples of the hydrophilic resin include gum arabic, casein, gelatin, starch derivatives, carboxymethyl cellulose and their Na salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers. , Polyacrylic acids and their salts, polymethacrylic acids and their salts, hydroxyethyl methacrylate homopolymers and copolymers, hydroxyethyl acrylate homopolymers and copolymers, hydroxypropyl methacrylate homopolymers and copolymers, hydroxypropyl acrylate homopolymers And copolymers, hydroxybutyl methacrylate homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers , Polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and homopolymers of hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide with a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight, and Examples thereof include copolymers, methacrylamide homopolymers and polymers, and N-methylolacrylamide homopolymers and copolymers.

The hydrophilic resin may be cross-linked and used as a waterproofing agent for curing. Glyoxal, melamine formaldehyde resin, aldehydes such as urea formaldehyde resin, N-methylol urea and N-methylol melamine, Methylol compounds such as methylolated polyamide resin, active vinyl compounds such as divinyl sulfone and bis (β-hydroxyethyl sulfonic acid), epichlorohydrin and polyethylene glycol diglycidyl ether, polyamide / polyamine / epichlorohydrin adduct, polyamide epichlorohydride Epoxy compounds such as phosphorus resin, ester compounds such as monochloroacetic acid ester and thioglycolic acid ester, polycarboxylic acids such as polyacrylic acid and methyl vinyl ether / maleic acid copolymer, Acid, titanyl sulfates, Cu,
Inorganic cross-linking agents such as Al, Sn, V and Cr salts, modified polyamide polyimide resin, etc. may be mentioned. In addition, a crosslinking catalyst such as ammonium chloride, a silane coupling agent, or a titanate coupling agent can be used in combination.

The amount of the hydrophilic resin added to the image forming layer is preferably 5 to 70%, more preferably 5 to 40% of the solid content of the image forming layer.
Is more preferable. Within this range, good on-press developability and film strength can be obtained, which is preferable.

(Photothermal Conversion Material) The image forming layer of the present invention comprises
In order to improve sensitivity, it contains a photothermal conversion substance that absorbs infrared rays and generates heat. As such a photothermal conversion substance, 7
Any light-absorbing substance having an absorption band in at least a part of 00 to 1200 nm may be used, and various pigments, dyes and fine metal particles can be used. When the photothermal conversion substance is added to the image forming layer, it may be added in the same layer as the image forming material of the present invention, in a separate layer, inside the particle or outside the particle.

As the pigment, commercially available pigments and color index (CI) handbook, "Latest Pigment Handbook" (edited by Japan Pigment Technology Association, 1977), "Latest Pigment Application Technology" (CMC Publishing, 1986) Infrared absorbing pigments described in "Printing Ink Technology" (CMC Publishing Co., Ltd., 1984) can be used.

These pigments can be used after being subjected to known surface treatments, if necessary, in order to improve the dispersibility in the layer to which they are added. The method of surface treatment includes a method of surface-coating a hydrophilic resin or a lipophilic resin, a method of attaching a surfactant, a reactive substance (for example, silica sol, alumina sol, a silane coupling agent or an epoxy compound,
For example, a method of binding an isocyanate compound or the like) to the surface of the pigment can be considered. The pigment added to the hydrophilic layer is easy to disperse with the water-soluble resin and does not impair the hydrophilicity,
It is desirable that the surface is coated with a hydrophilic resin or silica sol. The particle size of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm. As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production or the like can be used. Carbon black can be mentioned as a particularly preferable pigment.

As dyes, commercially available dyes and literatures (for example, "Dye Handbook" edited by The Society of Synthetic Organic Chemistry, published in 1970, "Chemical Industry", May 1986, "Near-infrared absorbing dyes"), P.45-51 Known dyes described in “Development of functional dyes in the 90's and market trends”, Chapter 2, Section 2.3 (1990) CMC) or patents can be used.
Specifically, azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes,
Infrared absorbing dyes such as carbonium dyes, quinone imine dyes, polymethine dyes, cyanine dyes are preferred.

Further, for example, JP-A-58-12524.
6, JP-A-59-84356, JP-A-60-787.
Cyanine dyes described in JP-A-87-58, JP-A-58-
173696, JP-A-58-181690, JP-A-58-194595, and other methine dyes,
JP-A-58-112793, JP-A-58-22479
3, JP-A-59-48187, JP-A-59-739.
96, JP-A-60-52940, and JP-A-60-63.
Naphthoquinone dyes described in JP-A No. 744, etc., squarylium dyes described in JP-A No. 58-112792, cyanine dyes described in British Patent 434,875, and dyes described in US Pat. No. 4,756,993. , U.S. Pat. No. 4,973,572, cyanine dyes, JP-A-10-268512, JP-A-11-23.
The phthalocyanine compound described in No. 5883 can be mentioned.

Further, as a dye, US Pat. No. 5,156,
The near-infrared absorption sensitizer described in US Pat. No. 938 is also preferably used, and the substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, JP-A-57-1.
Trimethine thiapyrylium salt described in No. 42645, JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, JP-A-59-84248, and JP-A-59-84.
No. 84249, No. 59-146063, No. 59-14.
No. 6061, a pyranium compound, a cyanine dye described in JP-A-59-216146, a pentamethine thiopyrylium salt described in U.S. Pat. No. 4,283,475, and Japanese Patent Publication No. 5-13514. Same as 5-1970
Pyrylium compounds disclosed in Japanese Patent Publication No. 2, Eporite III-178 and Eporite III-130 manufactured by Eporin Co., Ltd.
Epolite III-125 and the like are also preferably used. Among these, water-soluble dyes are preferable dyes to be added to the hydrophilic matrix such as the hydrophilic resin of the heat-sensitive layer, and specific examples are shown below. However, the present invention is not limited to these.

[0049]

[Chemical 13]

[0050]

[Chemical 14] Further, it is preferable that the photothermal conversion substance contains a photothermal conversion agent in the hydrophobic polymer fine particles to promote fusion between particles. It may be the above-mentioned photothermal conversion substance, but a lipophilic dye is more preferable. The following dyes can be mentioned as specific examples.

[0051]

[Chemical 15]

[0052]

[Chemical 16]

[0053]

[Chemical 17]

The above organic photothermal conversion agent can be added to the image forming layer in an amount of up to 30% by weight. It is preferably 5 to 25% by weight, particularly preferably 7 to 20% by weight.
Is. Within this range, good sensitivity can be obtained.

In the image forming layer and the like of the present invention, metal fine particles can be used as a photothermal conversion agent. Most of the metal fine particles are both photothermal conversion and self-heating.
Preferred metal fine particles are Si, Al, Ti, V, and C.
r, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr,
Mo, Ag, Au, Pt, Pd, Rh, In, Sn,
Examples thereof include fine particles of a simple substance of W, Te, Pb, Ge, Re, and Sb or an alloy thereof or an oxide or sulfide thereof.
Among the metals constituting these metal fine particles, a preferable metal has a melting point of about 100, which is easily fused by light irradiation.
Metals having absorption in the infrared, visible or ultraviolet region at 0 ° C or lower, such as Re, Sb, Te, Au, Ag, Cu, G
e, Pb and Sn. In addition, it is particularly preferable to use fine particles of a metal, such as Ag, Au, Cu, Sb, and Ge, which have a relatively low melting point and a relatively high absorbance for heat rays.
And Pb, particularly preferred elements are Ag, Au and Cu.

Further, for example, Re, Sb, Te, Au, A
Two or more types of photothermal conversion, such as mixing and using fine particles of a low melting point metal such as g, Cu, Ge, Pb, Sn and fine particles of a self-heating metal such as Ti, Cr, Fe, Co, Ni, W, and Ge. It may be composed of a substance. Also, Ag, Pt, Pd
It is preferable to use a micropiece of a metal species having particularly large light absorption when it is made into equal micropieces, and a combination of other metal micropieces.

The effect of the present invention is further exhibited by subjecting the surfaces of the above-mentioned fine particles of a simple metal or an alloy to a hydrophilic treatment. The means for making the surface hydrophilic is a compound which is hydrophilic and has adsorptivity to particles, for example, a surface treatment with a surfactant, a surface treatment with a substance having a hydrophilic group which reacts with the constituent substances of the particle, A method of providing a protective colloidal hydrophilic polymer film or the like can be used. Surface silicate treatment is particularly preferable. For example, in the case of iron fine particles, the surface can be made sufficiently hydrophilic by a method of immersing it in an aqueous solution of sodium silicate (3%) at 70 ° C. for 30 seconds. Other metal fine particles can be subjected to surface silicate treatment in the same manner.

The particle size of these particles is preferably 10 μm.
m or less, more preferably 0.003 to 5 μm, and particularly preferably 0.01 to 3 μm. Within this range, good sensitivity and resolution can be obtained, which is preferable.

In the present invention, when these metal fine particles are used as a photothermal conversion agent, the addition amount thereof is preferably 10% by weight or more, more preferably 20% by weight or more, particularly preferably 50% by weight of the solid content of the image forming layer. Used at 30% by weight or more. Within this range, high sensitivity is obtained, which is preferable.

Further, in the image forming layer of the present invention, a dye having a large absorption in the visible light region is used as a colorant for the image in order to make it easy to distinguish the image area from the non-image area after the image formation. You can Specifically, Oil Yellow # 1
01, oil yellow # 103, oil pink # 31
2, oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, crystal violet (CI42555), methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI
42000), methylene blue (CI52015), etc.
And the dyes described in JP-A No. 62-293247. Further, pigments such as phthalocyanine pigments, azo pigments, and titanium oxide can also be preferably used. The addition amount is preferably 0.01 to 10% by weight based on the total solid content of the coating liquid for the image forming layer.

Further, a plasticizer may be added to the image forming layer of the present invention, if necessary, in order to impart flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.

The image forming layer of the present invention is coated by preparing a coating solution by dissolving or dispersing the necessary components described above in a solvent. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol,
2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, Sulfolane, γ-
Butyl lactone, toluene, water, etc. can be mentioned, but not limited thereto. These solvents are
Used alone or as a mixture. The solid content concentration of the coating liquid is preferably 1 to 50% by weight.

The coating amount (solid content) of the image forming layer on the support obtained after coating and drying varies depending on the use,
Generally, 0.5 to 5.0 g / m ² is preferable. Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating and roll coating.

The image forming layer coating solution according to the present invention includes
Surfactants for improving coatability, for example, JP-A-6-61
Fluorine-based surfactants such as those described in 2-170950 can be added. The preferred addition amount is
The total solid content of the heat-sensitive layer is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight.

The lithographic printing plate precursor of the present invention protects the surface of the hydrophilic image forming layer from being contaminated by lipophilic substances during storage and contamination (fingerprint marks) due to contact with fingers during handling. Can be provided with a hydrophilic overcoat layer.

The hydrophilic overcoat layer used in the present invention can be easily removed on a printing machine, and is selected from water-soluble resins or water-swellable resins obtained by partially crosslinking the water-soluble resin. Contains.

The water-soluble resin is selected from water-soluble natural polymers and synthetic polymers, and is capable of forming a film when applied and dried using the water-soluble resin alone or with a crosslinking agent. Specific examples of the water-soluble resin preferably used in the present invention include natural polymers such as gum arabic, water-soluble soybean polysaccharides and fibrin derivatives (for example, carboxymethyl cellulose, carboxyethyl cellulose,
Methyl cellulose, etc.), its modified form, white dextrin, pullulan, enzymatically decomposed etherified dextrin, etc.
Among synthetic polymers, polyvinyl alcohol (polyvinyl acetate having a hydrolysis rate of 65% or more), polyacrylic acid,
The alkali metal salt or amine salt, polyacrylic acid copolymer, the alkali metal salt or amine salt, polymethacrylic acid, the alkali metal salt or amine salt,
Vinyl alcohol / acrylic acid copolymer and its alkali metal salt or amine salt, polyacrylamide, its copolymer, polyhydroxyethyl acrylate, polyvinylpyrrolidone, its copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer Polymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, its alkali metal salt or amine salt, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer, its alkali metal salt Alternatively, amine salts and the like can be mentioned. In addition, two or more kinds of these resins may be mixed and used depending on the purpose. However, the invention is not limited to these examples.

When at least one water-soluble resin is partially cross-linked to form an overcoat layer on the hydrophilic layer, the cross-linking is carried out by a cross-linking reaction using the reactive functional group of the water-soluble resin. . The cross-linking reaction may be a covalent bond or an ionic bond.

Crosslinking reduces the tackiness of the surface of the overcoat layer and improves the handleability of the lithographic printing plate, but if the crosslinking proceeds too much, the overcoat layer changes to lipophilicity and the overcoat on the printing machine is changed. Moderate partial cross-linking is preferred as it makes removal of the layer difficult.

Examples of the compound (crosslinking agent) used in the crosslinking reaction include known polyfunctional compounds having crosslinkability, such as polyepoxy compounds, polyamine compounds, polyisocyanate compounds, polyalkoxysilyl compounds, titanate compounds, Aldehyde compounds, polyvalent metal salt compounds,
Examples include hydrazine.

The crosslinking agents may be used alone or in admixture of two or more. Among the cross-linking agents, a particularly preferable cross-linking agent is a water-soluble cross-linking agent, but a water-insoluble cross-linking agent can be used by dispersing it in water with a dispersant.

Particularly preferred combinations of the water-soluble resin and the crosslinking agent include carboxylic acid-containing water-soluble resin / polyvalent metal compound, carboxylic acid-containing water-soluble resin / water-soluble epoxy resin, hydroxyl group-containing resin / dialdehydes. .

The preferred amount of the crosslinking agent added is 2% of the water-soluble resin.
10 to 10% by weight. Within this range, good water resistance can be obtained without impairing the removability of the overcoat layer on the printing machine.

In addition, a nonionic surfactant can be mainly added to the overcoat layer in the case of coating with an aqueous solution for the purpose of ensuring coating uniformity. Specific examples of such nonionic surfactants include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether, and polyoxyethylene dodecyl ether. . The proportion of the nonionic surfactant in the total solid content of the overcoat layer is preferably 0.05 to 5% by weight, more preferably 1 to 3% by weight.

The thickness of the overcoat layer of the present invention is from 0.1 μm to 4. When the water-soluble resin is not crosslinked.
0 μm is preferable, and a more preferable range is 0.1 μm to 1.0 μm. When the water-soluble resin is partially crosslinked, 0.1 to 0.5 μm is preferable, and 0.1 to 0.3 μm is preferable.
μm is more preferable. Within this range, contamination of the hydrophilic layer with a lipophilic substance can be prevented without impairing the removability of the overcoat layer on the printing machine.

In the lithographic printing plate precursor of the present invention, the support to which the image forming layer can be applied is a dimensionally stable plate-like material such as paper, plastic (eg polyethylene, polypropylene, polystyrene). Etc.) laminated paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate) , Polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films laminated or vapor-deposited with the above metals. As a preferable support, a polyester film or an aluminum plate can be mentioned.

The aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a slight amount of a different element, and further, a thin film of aluminum or an aluminum alloy is laminated with plastic. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc,
There are bismuth, nickel, titanium, etc. The content of foreign elements in the alloy is at most 10% by weight. However, as the aluminum plate applied to the present invention, an aluminum plate made of a conventionally known material can be appropriately used.

The thickness of the above substrate used in the present invention is 0.05 mm to 0.6 mm, preferably 0.1 mm to.
0.4 mm, particularly preferably 0.15 mm to 0.3 mm
Is.

Prior to using the aluminum plate, it is preferable to perform surface treatment such as surface roughening and anodic oxidation. By the surface treatment, it is easy to improve hydrophilicity and ensure adhesiveness with the heat-sensitive layer.

The surface roughening treatment of the aluminum plate is carried out by various methods. For example, mechanical surface roughening, electrochemical surface melting and surface roughening, and chemical surface roughening are performed. It is carried out by a method of selective dissolution. As the mechanical method, known methods such as a ball polishing method, a brush polishing method, a blast polishing method and a buff polishing method can be used. As a chemical method, a method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in JP-A-54-31187 is suitable. Further, as an electrochemical graining method, there is a method of performing alternating current or direct current in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Also, an electrolytic surface roughening method using a mixed acid as disclosed in JP-A-54-63902 can be used.

The surface roughening by the method as described above is carried out when the center line average roughness (Ra) of the surface of the aluminum plate is 0.2 to 1.
It is preferably applied in the range of 0 μm. The roughened aluminum plate is optionally subjected to alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide, etc., and further neutralized, and then, if desired, anodized to enhance wear resistance. Processing is performed. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes forming a porous oxide film can be used, and generally sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte. The treatment conditions for anodic oxidation cannot be unconditionally specified because it varies depending on the electrolyte used, but generally the concentration of the electrolyte is 1 to 80 wt% solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A /. It is suitable if the range is dm ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes. The amount of oxide film formed is 1.0 to 5.0.
g / m ^2, it is particularly preferably 1.5 to 4.0 g / m ^2.

The support used in the present invention may be the substrate which has been subjected to the above-mentioned surface treatment and has an anodized film as it is, but it has adhesiveness with the upper layer, hydrophilicity, stain resistance, and
To further improve heat insulation, etc.
No. 00-65219 and Japanese Patent Application No. 2000-143387, the expansion treatment of the micropores of the anodized film, the sealing treatment of the micropores, and the surface hydrophilization treatment by immersing in an aqueous solution containing a hydrophilic compound are appropriately performed. It can be done by choosing. Suitable hydrophilic compounds for the above-mentioned hydrophilic treatment include polyvinylphosphonic acid, compounds having sulfonic acid groups, saccharide compounds, citric acid, alkali metal silicates, potassium zirconium fluoride, phosphates / inorganic fluorine compounds, etc. Can be mentioned.

When a support such as a polyester film whose surface has insufficient hydrophilicity is used as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. The hydrophilic layer is described in Japanese Patent Application No. 2000-10810,
Applying a coating solution containing colloid of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metal. The hydrophilic layer formed by is preferable. Above all, a hydrophilic layer formed by applying a coating liquid containing a colloid of silicon oxide or hydroxide is preferable.

In the present invention, an inorganic undercoat layer described in Japanese Patent Application No. 2000-143387, such as a water-soluble metal salt of zinc borate, may be optionally added before coating the image forming layer. Or for example carboxymethyl cellulose,
An organic undercoat layer containing dextrin, polyacrylic acid or the like can be provided. Further, the undercoat layer may contain the photothermal conversion agent.

The lithographic printing plate precursor according to the invention can form an image by high power laser exposure, but a writing machine such as a thermal head may be used. Particularly in the present invention, it is preferable to use a laser emitting in the infrared or near infrared region. Particularly preferred is a laser diode which emits light in the near infrared region. Recording with an ultraviolet lamp is also possible, but in the present invention, the wavelength is 760 nm.
Image exposure is preferably performed by a solid-state laser and a semiconductor laser that emits infrared rays from 1 to 1200 nm. The laser output is preferably 100 mW or more, and it is preferable to use a multi-beam laser device in order to shorten the exposure time. The exposure time per pixel is preferably within 20 μsec. The energy applied to the recording material is preferably 10 to 300 mJ / cm ² .

The plate thus exposed is attached to a cylinder of a printing machine without a simple developing treatment such as water development or a dry method, or without treatment. The plate thus mounted without development processing can be printed by the following procedure. (1) A method of supplying dampening water to the printing plate, developing on the machine, and then supplying ink to start printing, (2) supplying dampening water and ink to the printing plate, and developing on the machine After that, there is a method of starting printing, (3) a method of supplying ink to the plate, supplying dampening water, and simultaneously supplying paper to start printing.

[0087]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited by these examples.

(Production of Aluminum Substrate) Aluminum of 99.5% or More, Fe 0.30%, Si 0.10
%, Ti 0.02%, Cu 0.013% JIS
A molten A1050 alloy was subjected to a cleaning treatment and cast.
For the cleaning treatment, degassing treatment was performed to remove unnecessary gas such as hydrogen in the molten metal, and ceramic tube filter treatment was performed. The casting method was a DC casting method. The solidified ingot with a thickness of 500 mm is ground by 10 mm from the surface,
A homogenizing treatment was performed at 550 ° C. for 10 hours so that the intermetallic compound did not become coarse. Then, after hot rolling at 400 ° C., intermediate annealing at 500 ° C. for 60 seconds in a continuous annealing furnace, cold rolling was performed to obtain an aluminum rolled plate having a plate pressure of 0.30 mm. By controlling the roughness of the rolling roll, the center line average surface roughness Ra after cold rolling is 0.2 μm.
Controlled to. Then, a tension leveler was applied to improve the flatness.

Next, a surface treatment was carried out to obtain a lithographic printing plate support. First, in order to remove the rolling oil on the surface of the aluminum plate, degreasing treatment was performed with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, neutralization with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds, and smut removal treatment.

Next, in order to improve the adhesion between the support and the image-forming layer and to impart water retention to the non-image area, the surface of the support was roughened, that is, a so-called graining treatment was performed. 1
% Aqueous solution containing 5% nitric acid and 0.5% aluminum nitrate
While keeping the temperature at 5 ° C., while flowing the aluminum web in the aqueous solution, an anode side electricity quantity of 240 C / d with an alternating waveform of a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect power supply cell.
Electrolytic graining was performed by giving m ² . Then 10
% Sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and 30 %% sulfuric acid aqueous solution at 50 ° C. for 30 seconds for neutralization and smut removal treatment.

Further, in order to improve wear resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. Anodized film of 2.5 g / m ² is obtained by using a 20% aqueous solution of sulfuric acid as an electrolyte at 35 ° C. and carrying out an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power supply cell while carrying the aluminum web through the electrolyte. It was created. After that, a silicate treatment was performed in order to secure hydrophilicity as a non-image portion of the printing plate. The treatment was carried out by keeping a 1.5% aqueous solution of sodium silicate No. 3 at 70 ° C. so that the contact time of the aluminum web was 15 seconds, and further washing with water. The amount of Si deposited is 10 mg
/ M ² . The center line surface roughness Ra of the support produced as described above was 0.25 μm.

[Examples 1 to 5] Compositions having the following weight ratios were dispersed with glass beads for 10 minutes to prepare carbon black dispersions.

[0093] (Carbon black dispersion)     Carbon black (particle size 0.2-0.3 μm) 1.0 part by weight     Copolymer of benzyl methacrylate and methacrylic acid 1.6 parts by weight     (Molar ratio 72:29, weight average molecular weight 70,000)     Methyl ethyl ketone 1.6 parts by weight     1-methoxy-2-propanol 3.8 parts by weight

(Preparation of negative lithographic printing plate precursor)] The aluminum substrate obtained above was coated with a photosensitive liquid (image forming layer coating liquid) having the following composition and dried at 70 ° C. for 5 minutes to form an image. Layers were formed to obtain a negative lithographic printing plate precursor. The weight of the image forming layer after drying was 2.0 g / m ² .

[0095] (Photosensitive liquid)     2.4 g of the carbon black dispersion    Copolymer of allyl methacrylate and methacrylic acid 1.65 g   (Molar ratio 80:20, weight average molecular weight 30,000)    0.55 g of the additive compound described in Table 1    Megafac F-176 (manufactured by Dainippon Ink and Chemicals, Inc.) 0.06g    Methyl ethyl ketone 15g    2-methoxy-1-propanol 12 g

The negative-working photosensitive lithographic printing plate thus obtained was equipped with a water cooling type 40 W infrared semiconductor laser and manufactured by Creo Trends.
etter 3244VFS output 9W, external drum rotation speed 2
10 rpm, plate energy 500 mJ / m ² , resolution 24
After exposure under the condition of 00 dpi, Fuji Photo Film Co., Ltd.
Developer, DP-4 (1: 8), rinse solution FR-3
When processed through an automatic developing machine charged with (1: 7), a negative image was obtained. The developing solution in this case is alkaline water (pH about 13). This lithographic printing plate was printed on a Heidel SOR-KZ machine and evaluated. The results are shown in Table 1 below.

Comparative Example 1 A copolymer of allyl methacrylate and methacrylic acid (molar ratio 80: 2) was used except for the compound (1) in the photosensitive solution described in Table 1 used in Example 1.
0, weight average molecular weight 30,000) 0.55 g except that the negative type lithographic printing plate was prepared in the same manner as in Example 1 and subjected to image formation and printing evaluation. The results are shown in Table 1.

[0098]

[Table 1]

(Additional Compounds in Table 1) The additional compounds described in Table 1 are shown below.

[0100]

[Chemical 18]

Examples 1 to 1 using the polymer compound of the present invention
In No. 5, good printed matter was obtained, but in Comparative Example 1, the photosensitive film was completely dissolved in the developing solution, and no image was obtained.

[Examples 6 to 10] (Synthesis example of fine particle dispersion) 2 g of the additive compound described in Table 2 as an oil phase component and a phenol novolac resin having a weight average molecular weight of 1500 (meta / para ratio: 60/40). 4g,
Light-to-heat conversion substance (IR-26) 1.5 g, and anionic surfactant Pionin A-41C (manufactured by Takemoto Yushi Co., Ltd.) 0.1
g to methyl ethyl ketone 7.4 g and ethyl acetate 1
After being dissolved and dispersed in 3.7 g, a 1.8% aqueous solution of polyvinyl alcohol (PVA205 manufactured by Kuraray Co., Ltd.) as an aqueous phase component 5
Mix to 3g and homogenize at 15000 rpm for 10
It was emulsified and dispersed for a minute. Then, methyl ethyl ketone and ethyl acetate were evaporated while stirring at 40 ° C. for 3 hours. The solid content concentration of the obtained fine particle dispersion was 15.4% by weight. The average particle size was 0.30 μm.

On the support obtained in the above Production Example, a photosensitive solution (image forming layer coating solution) containing the fine particles of Synthesis Example and having the following composition was prepared, and then bar coating was carried out, followed by 60 in an oven.
It was dried at 120 ° C. for 120 seconds to prepare a lithographic printing plate precursor having a dry coating amount of the image forming layer of 1 g / m ² .

(Photosensitive liquid) 25 g of water Fine particle dispersion (Synthesis example above) 20 g

The lithographic printing plate precursor thus obtained was subjected to Creo equipped with a water-cooled 40 W infrared semiconductor laser.
With a Trendsetter 3244 VFS manufactured by the same company, the output is 9 W, the outer surface drum rotation speed is 210 rpm, the plate surface energy is 300 mJ / m ² ,
After exposure at a resolution of 2400 dpi, it was attached to the cylinder of the Heidelberg printer SOR-M without developing, supplying dampening water, supplying ink, and then supplying paper to perform printing. It was As a result, it was possible to carry out on-press development for all the printing original plates without problems, and printing was possible. The number of printable sheets of each printing plate is shown in Table 2.

Comparative Example 2 Epicoat 1 was used except for the compound (6) in the photosensitive solution described in Table 2 used in Example 6.
A fine particle dispersion and a printing plate using the same were prepared in the same manner as in Example 6 except that the same amount of 009 was added, and image formation and printing evaluation were performed. The results are shown in Table 2.

[0107]

[Table 2]

(Additional Compounds in Table 2) The additional compounds described in Table 2 are shown below.

[0109]

[Chemical 19]

Example 6 using the polymer compound of the present invention
In No. 10, good printed matters were obtained and the printing durability (the number of printed sheets) was also good, but in Comparative Example 1, the printing durability was unsatisfactory.

[0111]

As described above, the image forming material of the present invention contains at least one of the compounds having the structures represented by the general formulas (I) to (III), and causes a chemical reaction by heating. , Having a cross-linking agent that easily generates a highly reactive isocyanate, by the heat generated by irradiation of laser exposure, the generated isocyanate is a compound having a nucleophilic group in the image forming layer,
Alternatively, it reacts with an amine produced by self-hydrolysis with water to form a strong film and is made water resistant. In the unexposed area, each compound is dispersed in the hydrophilic polymer in the form of particles or / and solid dispersion, so that it can be easily removed by an aqueous developer, and heat-sensitive image formation can be easily performed. is there. Therefore, the development process such as water development or alkali development method or the development process is not required, and the plate can be directly mounted on the printing machine to perform plate making / printing, and hydrophobic / hydrophilic discrimination (identification) It is possible to provide a lithographic printing plate precursor that is high in ink receptivity and good in printing durability and can obtain clear printed matter. Further, the image-forming material of the present invention has a structure in which the reactive isocyanate group is made into a precursor, and has an effect that a lithographic printing plate precursor having improved storage stability can be obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H025 AA01 AA11 AA12 AA13 AB03                       AC08 AD01 BD06 BH00 BJ03                       CC20 DA36 FA10                 2H096 AA06 BA01 BA20 CA03 EA04                       EA23                 2H114 AA04 AA22 AA24 BA01 DA03                       DA04 DA26 DA52 DA73 DA78                       EA01 EA03 EA05 FA16 GA03                       GA05 GA06 GA08 GA09 GA34                       GA38

Claims (2)

[Claims] 1. An image-forming material comprising at least one compound selected from the compounds represented by the following general formulas (I) to (III). [Chemical 1] (In formulas (I) to (III), R ₁ represents an n-valent organic residue (n is an integer of 2 to 8), and R _{2 to} R ₄ represent an alkyl group.
X represents a leaving group bonded to N by an oxygen atom, Y represents a hydrogen atom, a metal atom or a trialkylsilyl group, and Ar represents an aromatic group. ) 2. On the hydrophilic support, the compounds of the general formula (I) to
A lithographic printing plate precursor having an image forming layer comprising fine particles containing at least one compound represented by (III).